Assessment of adiposity in psoriatic patients by dual energy X-ray absorptiometry compared to conventional methods

Abstract

BACKGROUNDObesity is considered a chronic low-grade inflammatory disease that shares mediators of inflammation with psoriasis, such as TNF-α and IL-6. The relationship between these two conditions involves factors such as predisposition and response to therapy, in addition to an association with cardiovascular disease.OBJECTIVESThe aim of the present study was to investigate the prevalence of adiposity as determined by body mass index (BMI), waist circumference (WC), and dual energy X-ray absorptiometry (DXA) evaluation in patients with psoriasis.METHODSBMI, WC and body composition by DXA were measured in 42 psoriatic patients without joint complaints and in 41 control patients using standard procedures. In the comparison between cases and controls, we used Pearson’s Χ2 test or Fisher’s exact test, and the nonparametric Mann-Whitney test. The difference between the diverse classification methods for obesity was evaluated using McNemar’s test. To test the level of agreement between those variables, we used the weighted kappa coefficient.RESULTSThere was no difference in the prevalence of obesity among cases and controls. Both BMI and WC had low agreement with measures of body fat evaluated by DXA. With the use of DXA scanning, prevalence of overweight and obesity in patients with psoriasis was 83.3%, which constitutes a strong evidence of the need for intervention on this metabolic parameter.CONCLUSIONDual energy X-ray absorptiometry was more capable of identifying obesity compared with BMI and WC both in psoriatic and control patients.

The performance of anthropometric tools to determine obesity: a systematic review and meta-analysis

“…1) . Twenty-seven studies (29 articles) assessed BMI 44,[46][47][48][49][50][51][52][53][54][58][59][60][61][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] , and 15 (19 articles) reported on waist measurements such as WC [43][44][45][46][47][49][50][51][52][53][57][58][59][60]62,63 , WHR [43][44][45][46][47][49][50]…”

“…Fourteen studies were community-based 44,46,51,58,[62][63][64][66][67][68]70,73,75,76,78 , fourteen were primary care-or hospitalbased 45,47,49,50,[52][53][54]57,[59][60][61]69,72,74,77 , two were community-and hospital-based 43,48,55,56 , one study was based in the army 65 and one did not report its setting 71 . Six studies included patients with various diseases or physical or cognitive disabilities 50,[52][53][54]59,61,66,74 . Four studies stratified analyses by age groups 43,44,46,55,56,58...…”

“…Of the included studies, we rated the risk of bias for six as low 52,53,58,60,63,67,70 , for 16 as unclear [43][44][45][46][47][54][55][56][57]59,62,65,66,69,71,[73][74][75]77 and for ten as high [48][49][50][51]61,64,68,72,76,78 . The reasons for the high risk of bias ratings included convenience sampling, inappropriate exclusion criteria for study participants and lack of predefined thresholds for index and reference tests.…”

“…The reasons for the high risk of bias ratings included convenience sampling, inappropriate exclusion criteria for study participants and lack of predefined thresholds for index and reference tests. Eleven studies were conducted in Asia 44,46,47,49,51,60,63,68,70,71,75,78 , ten studies in North America 50,[52][53][54]58,65,66,[72][73][74]77 , eight in South America 43,45,[55][56][57]59,61,62,67,69 and three 48,64,76 in Europe. Twenty-two studies were publicly funded, eight studies did not report their funding 48,49,64,65,68,69,71,76 and two received sponsoring from pharmaceutical companies 57,61 .…”

“…The 27 included studies 44,[46][47][48][49][50][51][52][53][54][58][59][60][61][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] reported varying cut-offs for BMI to determine obesity. Thresholds ranged from 19.6 to 30 kg/m 2 for women and from 23.5 to 30 kg/m 2 for men.…”